Water flooding is a conventional process of enhancing the extraction of hydrocarbon materials (e.g., crude oil, natural gas, etc.) from a subterranean formation. In this process, an aqueous fluid (e.g., water, brine, etc.) is injected into the subterranean formation through injection wells to sweep a hydrocarbon material contained within interstitial spaces (e.g., pores, cracks, fractures, channels, etc.) of the subterranean formation toward production wells. One or more additives may be added to the aqueous fluid to assist in the extraction and subsequent processing of the hydrocarbon material.
For example, in some approaches, a surfactant, solid particles (e.g., as colloids), or both, are added to the aqueous fluid. The surfactant and/or the solid particles can adhere to or gather at interfaces between a hydrocarbon material and an aqueous material to form a stabilized emulsion of one of the hydrocarbon material and the aqueous material dispersed in the other of the hydrocarbon material and the aqueous material. Surfactants may decrease the surface tension between the hydrocarbon phase and the water phase, such as in an emulsion of a hydrocarbon phase dispersed within an aqueous phase. Stabilization by the surfactant, the solid particles, or both, lowers the interfacial tension between the hydrocarbon and water and reduces the energy of the system, preventing the dispersed material (e.g., the hydrocarbon material, or the aqueous material) from coalescing, and maintaining the one material dispersed as units (e.g., droplets) throughout the other material. Reducing the interfacial tension increases the permeability and the flowability of the hydrocarbon material. As a consequence, the hydrocarbon material may be more easily transported through and extracted from the subterranean formation as compared to water flooding processes that do not employ a surfactant and/or solid particles. The effectiveness of the emulsion is determined in large part by the ability of the emulsion to remain stable and ensure mixing of the two phases.
However, application of surfactants is usually limited by the ability of the surfactant to sufficiently contact a large portion of a volume of hydrocarbons located within the subterranean formation and form an emulsion containing the hydrocarbons and the aqueous material carrying the surfactants. For example, the surfaces of the hydrocarbon-containing reservoir may not be sufficiently contacted by the surfactants, or the surfactants may not sufficiently adhere to hydrocarbon-bearing surfaces of the subterranean formation.